Biogas production in rural areas of Mexico

Sammanfattning: Mexico is highly dependent on fossil fuels. One of the governmental initiatives proposes to investigate the possibilities for biogas production in rural areas. Agricultural producers are highly susceptible to energy price variations and in most cases the steadily growing prices of electricity and fuels are lowering the profits and income of farmers. Environmental concerns about fossil fuels give additional stimulus towards a switch to more sustainable energy sources. Literature research on different types of biogas production technologies was carried out. Various anaerobic fermentation stages and techniques were studied in order to familiarise with particular features and to understand which of them will be more suitable for locations in rural Mexico, also taking into account the local conditions, availability of raw material, energy demands, etc. Mexico's agricultural policies and governmental support schemes were also studied. The agricultural sector in Mexico is strategically important and brings around 6% of the country's GDP. Security and availability of energy for the rural areas is crucial. A lot of improvements need to be done in this field to make this sector attractive for investors and more profitable for people who already work there. Such governmental organizations as SAGARPA - The Secretariat of Agriculture, Livestock, Rural Development, Fishing, and Food - and its support schemes and programs are aimed to help farmers both financially and technically to overcome the difficulties concerning this procedure. A detailed description of a proposed biogas production plant for a case study project at a milk farm in southern Mexico is presented in this study. Different stages and control strategies of biogas production as well as possibilities for biogas utilization in a small-scale CHP unit are assessed. Economical study was aimed to determine the financial flows of the sample project. A simplified economic analysis showed that the electricity produced in the biogas-driven CHP unit can compete with actual grid electricity prices. In addition, comparatively short payback time could be expected and the available governmental support schemes could be efficiency exploited for a commercially viable biogas production.